Apneic Events Research Articles

Is cellular energy monitoring more responsive to hypoxia than pulse oximetry?

PurposePulse oximetry is the current standard for detecting drops in arterial blood oxygen saturation (SpO2) associated with obstructive sleep apnea and hypopnea events in polysomnographic (PSG) testing. However, cellular energy monitoring (CE monitoring), a measure related to cellular hypoxia in the skin, is likely to be more responsive to inadequate breathing during sleep because during hypoxic challenge, such as occurs during apneic events, regulatory mechanisms restrict blood flow to the skin to preferentially maintain SpO2 for more vital organs. We carried out initial proof of concept testing to determine if CE monitoring has promise for being more responsive to hypoxic challenge occurring during sleep-disordered breathing (SDB) than pulse oximetry.MethodsWe assessed both CE monitoring and pulse oximetry in a series of conditions which affect oxygen supply: (1) breathing nitrogen or 100% oxygen, (2) physical exertion, and (3) studying a night of sleep in an individual known to be a loud snorer. We also present the results of a preliminary study comparing CE monitoring to pulse oximetry in eight individuals undergoing standard clinical overnight polysomnography for suspected SDB.ResultsCE monitoring is responsive to changes in cellular oxygen supply to the skin and detects hypoxia during SDB events that is not detected by pulse oximetry.ConclusionCE monitoring is a promising tool for identifying pathology at the mild end of the SDB spectrum.

Multispectral Video Fusion for Non-Contact Monitoring of Respiratory Rate and Apnea.

Continuous monitoring of respiratory activity is desirable in many clinical applications to detect respiratory events. Non-contact monitoring of respiration can be achieved with near- and far-infrared spectrum cameras. However, current technologies are not sufficiently robust to be used in clinical applications. For example, they fail to estimate an accurate respiratory rate (RR) during apnea. We present a novel algorithm based on multispectral data fusion that aims at estimating RR also during apnea. The algorithm independently addresses the RR estimation and apnea detection tasks. Respiratory information is extracted from multiple sources and fed into an RR estimator and an apnea detector whose results are fused into a final respiratory activity estimation. We evaluated the system retrospectively using data from 30 healthy adults who performed diverse controlled breathing tasks while lying supine in a dark room and reproduced central and obstructive apneic events. Combining multiple respiratory information from multispectral cameras improved the root mean square error (RMSE) accuracy of the RR estimation from up to 4.64 monospectral data down to 1.60 breaths/min. The median F1 scores for classifying obstructive (0.75 to 0.86) and central apnea (0.75 to 0.93) also improved. Furthermore, the independent consideration of apnea detection led to a more robust system (RMSE of 4.44 vs. 7.96 breaths/min). Our findings may represent a step towards the use of cameras for vital sign monitoring in medical applications.

Caffeine Citrate for the Prevention of Apnea Associated With Alprostadil Infusions.

To evaluate the incidence of apnea and requirement for positive pressure ventilation in patients who received caffeine for prevention while receiving alprostadil compared with those who did not receive caffeine. This was a single-center, retrospective study of patients who received alprostadil over a 7-year time frame. Patients were divided into 2 groups based on whether they received caffeine for prevention of apnea while receiving alprostadil. The incidence of apnea and requirements for positive pressure ventilation were recorded. A total of 64 patients who received alprostadil were included for review. Thirty-two patients received caffeine for the prevention of apnea, and 32 patients received alprostadil only. Alprostadil doses were similar between the 2 groups (0.04-0.05 mcg/kg/min). Seven patients had a documented apneic event; 3 in the group given caffeine and 4 in the control group. One patient in each group required intubation because of apnea. All patients with documented apnea were on low-dose alprostadil therapy (<0.05 mcg/kg/min). Three patients had apnea after dose reductions had been made. Six out of the seven patients experienced apnea within the first 24 hours after the infusion. Only 1 patient experienced multiple apneic events. In this small sample, there was no difference in incidence of apnea between patients on low-dose alprostadil who received caffeine for prevention and those who did not. Despite the use of low-dose alprostadil therapy and dose reductions, the incidence of apnea remains low, and most patients did not have repeated apneic events or require intubation.

Spinal cord injury leads to increases in apnea frequency and duration in spontaneously breathing mice with and without central nervous system 5HT

PurposeThe present investigation was designed to explore the impact of serotonin (5HT) on apnea severity and duration, arousal frequency and respiratory stability following spinal cord injury (SCI) in mice.MethodsTelemetry transmitters were surgically implanted in wild type mice (Tph2+/+) (n = 4) and tryptophan hydroxylase 2 knockout mice (Tph2−/−) (n = 3) to measure electroencephalography, core body temperature and gross motor activity. Following recovery, the Tph2+/+ and Tph2−/− mice were placed in whole body plethysmographs and measures of apnea severity, coefficient of variation of the duration of each breath, duration index and arousal frequency during non‐rapid eye movement sleep were determined for 6 hours. Following these measures, a C2 hemisection of the spinal cord was completed and the physiological measurements were repeated 4 and 21 days following hemisection.ResultsFollowing SCI the number of apnea events increased in the Tph2+/+ (baseline vs. 21 days: 52.1 ± 17.4 vs. 106.4 ± 21.2 events/hr, p = 0.02) and the Tph2−/− mice (30.7 ± 9.6 vs. 77.5 ± 34.1, p = 0.02). The coefficient of variance of the duration of each breath also increased after SCI (Tph2+/+ 0.25 ± 0.02 vs. 0.30 ± 0.06, Tph2−/− 0.25 ± 0.02 vs. 0.35 ± 0.06, p = 0.07). Likewise, the apnea duration index increased following SCI in the Tph2+/+ (baseline vs. 21 days: 2.4 ± 0.05 vs. 3.2 ± 0.6 events/hr, p = 0.047) and Tph2−/− mice (baseline vs. 21 days: 2.6 ± 0.5 vs. 3.8 ± 0.5 events/hr, p = 0.047). Lastly, the number of arousals increased after SCI in both groups (Tph2+/+ 19.0 ± 4.6 vs. 39.1 ± 13.8, Tph2−/− 5.1 ± 0.9 vs. 35.6 ± 19.4 arousal/hr, p = 0.03).ConclusionsSCI leads to an increase in the frequency and duration of apneic events, which is coupled to an increase in the number of arousals. Likewise, alterations in the coefficient of variation indicate that breathing is more variable when present. However, the role of 5HT in mediating arousals and stabilizing breathing is less certain in this small sample size, since modifications in breathing stability and arousal frequency was not statistically different in the Tph2+/+ and Tph2−/− mice following SCI.Support or Funding InformationDepartment of Veterans Affairs (I01BX003946 &amp; 15SRCS003 JHM)

Light or Deep Pressure: Medical Staff Members Differ Extensively in Their Tactile Stimulation During Preterm Apnea.

Background: Even though tactile stimulation is common practice to terminate preterm apnea, the style and intensity of these interventions is not specified during theoretical or practical training and has never been clinically evaluated.Objective: The present study was designed to analyze the various modes of tactile stimulation used to terminate preterm apnea and measure the pressure intensity and frequency of these stimulations.Methods: A model with the size and weight of an actual preterm infant was equipped with sensor technology to measure stimulation pressure and frequency of tactile stimulation. Additionally a camera system was used to record hand positions and stimulation modes. Seventy medical staff members took part in the experiment.Results: We found extreme between subjects differences in stimulation pressure that could not be explained by professional experience but, to a degree, depended on apnea intensity. Pressures ranged from 11.11 to 226.87 mbar during low intensity apnea and from 9.89 to 428.15 mbar during high intensity apnea. The majority of participants used rhythmic stimulation movements with a mean frequency of ~1 Hz. Different modes (rubbing, squeezing, tickling, and tapping) and finger positions were used.Conclusion: Medical staff members intuitively adjust their tactile stimulation pressure depending on the premature infants' apnea intensity. However, mean pressure values varied greatly between subjects, with similar pressure ranges for low and high intensity apnea. The question remains which pressure intensities are necessary or sufficient for the task. It is reasonable to assume that some stimulation types may be more effective in rapidly terminating an apneic event.

Abstract P391: The Effects of Obstructive Sleep Apnea on Cardiac Arrhythmia Risk

Background: Over 20 million people in the United States suffer from Obstructive Sleep Apnea (OSA). Compared to the general population, OSA patients are 2.6 times more likely to experience sudden cardiac death (SCD), and it is suspected that this is due, in part, to QT prolongation leading to fatal dysrhythmias. OSA events have previously been shown to cause prolonged QT intervals compared to the post-apnea hyperventilation period, and studies have also observed increased QT dispersion in patients without cardiac disease. However, those with cardiac disease may be at the greatest risk for SCD, and it is not known what role QT prolongation plays and what factors influence these responses. Thus, the purpose of this study is to evaluate the factors that affect QT interval during periods of sleep apnea including OSA severity, time of night, and quantity of obstructive apneic events during sleep. Methods: We determined QTc intervals from the electrocardiograms of 36 patients undergoing polysomnography for diagnosis of OSA. Patients that were selected had an apnea hypopnea index &gt;20/Hr and had no prior myocardial infarction or heart failure. Each patient’s ECG during their sleep study was analyzed to assess QT interval throughout the night. Baseline QT intervals were compared to QT intervals during obstructive apneas during the first 2 hours of sleep (Early) and last 2 hours of sleep (Late). In addition, apneas &gt;40 seconds were analyzed in 11 patients for changes in QTc as the apnea progressed. Statistical comparisons were made with paired t tests and a one-way ANOVA analysis with repeated measures. Results: Early analyses of data showed QTc intervals in Early and Late apneas were significantly prolonged compared to awake baseline (p=0.04 and p=0.006 respectively). For patients with apneas &gt;40 seconds, significant differences in QTc interval were observed at increasing time points during the apnea compared to the QTc immediately preceding the apnea (p&lt;0.001). Furthermore, patients with longer apneas tend to have longer baseline QTc (p=0.07). Conclusions: Sleep apneic events are associated with periods of mild QTc prolongation despite some cardiac cycle shortening. The prolongation tends to become enhanced later in the night, implying that there is a cumulative effect of numerous prior apneas. Furthermore, prolongation tends to increase as the apnea duration progresses. Early data analyses also suggest that baseline QTc tends to be longer in patients who have more severe/longer apneic events throughout the night. Future studies will focus on QTc changes in OSA patients with prior heart disease, as these are the patients at greatest risk for serious arrhythmias during the night.

Continuous intraocular pressure monitoring in patients with obstructive sleep apnea syndrome using a contact lens sensor.

PurposeTo analyse nocturnal intraocular pressure (IOP) fluctuations in patients with obstructive sleep apnea syndrome (OSAS) using a contact lens sensor (CLS) and to identify associations between the OSAS parameters determined by polysomnographic study (PSG) and IOP changes.MethodProspective, observational study. Twenty participants suspected of having OSAS were recruited. During PSG study, IOP was monitored using a CLS placed in the eye of the patient. The patients were classified according to the apnea-hypopnea index (AHI) in two categories, severe (>30) or mild/moderate (<30) OSAS. We evaluated several parameters determined by the IOP curves, including nocturnal elevations (acrophase) and plateau times in acrophase (PTs) defined by mathematical and visual methods.ResultsThe IOP curves exhibited a nocturnal acrophase followed by PTs of varying extents at which the IOP remained higher than daytime measurement with small variations. We found significant differences in the length of the PTs in patients with severe OSAS compared to those with mild/moderate disease (P = 0.032/P = 0.028). We found a positive correlation between PTs and OSAS severity measured by the total number of apneic events (r = 0.681/0.751 P = 0.004/0.001) and AHI (r = 0.674/0.710, P = 0.004/0.002). Respiratory-related arousal and oxygen saturation also were associated significantly with the IOP PT length.ConclusionsPeriods of nocturnal IOP elevation lasted longer in severe OSAS patients than those with mild/moderate OSAS and correlate with the severity of the disease. The length of the nocturnal PT is also associated to respiratory parameters altered in patients with OSAS.

Obstructive sleep apnea intensifies stroke severity following middle cerebral artery occlusion

Study objectivesObstructive sleep apnea (OSA) is a sleep disorder caused by transient obstruction of the upper airway and results in intermittent hypoxia, sleep fragmentation, sympathetic nervous system activation, and arousal which can have an adverse effect on cardiovascular disease. It is theorized that OSA might intensify stroke injury. Our goal here was to develop a new model of experimental OSA and test its ability to aggravate behavioral and morphological outcomes following transient brain ischemia/reperfusion. MethodsWe used a 3D printed OSA device to expose C57BL6 mice to 3 h of OSA (obstructive apnea index of 20 events per hour) for three days. These mice were then subjected to ischemia/reperfusion using the middle cerebral artery occlusion model (MCAO) stroke and examined for overall survival, infarct size and neurological scoring. ResultsWe found that OSA transiently decreased respiration and reduced oxygen saturation with bradycardia and tachycardia typical of human responses during apneic events. Brain injury from MCAO was significantly increased by OSA as measured by infarct size and location as well as by intensification of neurological deficits; mortality following MCAO was also increased in OSA animals. ConclusionsOur findings suggest that our new model of OSA alters respiratory and cardiovascular physiological functions and is associated with enhanced ischemia/reperfusion mediated injury in our non-invasive, OSA intensified model of stroke.

Exploring the STOP-BANG questionnaire for obstructive sleep apnea screening in seniors.

The accuracy of obstructive sleep apnea (OSA) screening instruments in seniors may change as the predictive role of sex, age, and body mass index (BMI) changes with aging. We investigated the diagnostic performance of the STOP-BANG questionnaire in older individuals with aging-adapted scores and thresholds. Independent community-dwelling adults aged 65 years or older were screened for OSA. The STOP-BANG questionnaire was tested with different configurations and compared to the apnea-hypopnea index (AHI) obtained from home sleep apnea testing (HSAT). Epworth Sleepiness Scale (ESS) and Athens Insomnia Scale (AIS) were tested as possible supplementary screening criteria. We recruited 458 individuals with a mean age of 71 ± 5 years, 41% men, BMI of 28.5 ± 4.6 kg/m². Mild, moderate, and severe OSA were present in, respectively, 34%, 30%, and 19% of the sample. The STOP questions had an area under the curve (AUC) of the receiver operating characteristic curve significantly lower than the STOP-BANG and the STOP+BMI > 28 kg/m² (STOP-B28). Both STOP-BANG and STOP-B28 had high sensitivity and low specificity in all OSA levels with similar AUC to predict AHI ≥ 5 events/h, 0.64. ESS and AIS were nonsignificant as adjunctive instruments. Novel modifications of a standard instrument created the STOP-B28, a simpler-to-obtain and similarly performing variation of the STOP-BANG using fewer inputs, and useful to exclude OSA. Screening seniors via questionnaires to detect OSA is problematic. Considering the 83% OSA prevalence in this age group, it may be a sensible option to indicate objective tests, oximetry, HSAT, or even polysomnography, as a first step in OSA investigation.

Evaluation of Nocturnal Respiratory Complaints in Pregnant Women.

Snoring during pregnancy increases the risk of low Apgar score and low birth weight of newborns. Snoring women are twice as likely to be diagnosed as having preeclampsia when compared to non-snoring ones. Snoring may also be linked to, albeit it is not a prerequisite for, apneic events at sleep. The aim of this survey-type study was to evaluate the occurrence and severity of nocturnal respiratory complaints in a group of 312 pregnant women. Problems associated with snoring and other nasopharyngeal symptoms were reported by 60% of women. Complaints were more frequent in patients with a higher body mass index. The symptoms were significantly more frequent in the group of snorers. The results of this study suggest a pattern of basic features in pregnancy, such as snoring, overweight, and upper airway symptoms, which all ought to direct attention of care givers to the diagnostics of sleep-related breathing disorders. The early diagnosis would enable to undertake the measures to prevent preterm labor and to avoid postpartum complications in both mother and newborn.

Management of apnea in infants with trisomy 18.

This case series aimed to characterize the clinical features, management, and outcomes of apnea in infants with trisomy 18. Participants in this study were infants with trisomy 18 who were born alive and admitted to the neonatal intensive care unit in Kyushu University Hospital from 2000 to 2018. Retrospective analysis was performed on clinical data recorded in our department. Twenty-seven infants with trisomy 18 were admitted to our hospital during the study period, of which 25 (nine males, 16 females) were enrolled as eligible participants in this study. Among them, 14 started presenting with apnea from median 3.5days of age (range 0-47d). In these infants with apnea, eight received respiratory support of positive pressure ventilation (PPV). The 1-year survival rate of infants in the PPV group was higher than that of non-PPV-supported infants (5 out of 8 vs 0 out of 6 infants). Five PPV-supported infants received a diagnosis of epilepsy, which was controlled by antiepileptic drugs. Postnatal respiratory intervention provides better prognosis in infants with trisomy 18. Improved survival leads to accurate diagnosis and treatment of apneic events in association with epilepsy. WHAT THIS PAPER ADDS: Respiratory support is effective against apnea in infants with trisomy 18. Intervention with ventilation provides a higher chance of prolonged survival. Improved survival leads to the accurate diagnosis and treatment of epilepsy-associated apnea.

A comparison of ventilation with a non-invasive ventilator versus standard O2 with a nasal cannula for colonoscopy with moderate sedation using propofol.

The aim of this study was to test the effects of CPAP on moderately sedated patients undergoing colonoscopy. Our hypothesis was that CPAP can reduce the incidence and duration of obstructive apnea and hemoglobin oxygen desaturation in patients undergoing procedural sedation for colonoscopy. Two groups of consenting adult patients scheduled to undergo routine colonoscopy procedures and sedated with propofol and fentanyl were monitored in this study: control and intervention. Patients in the intervention group were connected via a facemask to a ventilator that delivered supplemental oxygen (100%) through a standard air-cushion mask. The mask had a built-in leak to facilitate CO2 clearance during CPAP. Patients in the control group received 2-10 L/min of oxygen via nasal cannula or non-rebreather mask. Subjects in the control group were collected in a prior study and used as historical controls. The primary outcome measures were the number of apneic events and the cumulative duration of apneic events. An apneic event was defined as a period longer than 10s without respiration. The secondary outcome was the area under the curve (AUC) for the arterial oxygen saturation less than 90% versus time during sedative and analgesic administration (time (s) below threshold multiplied by percent below threshold). A desaturation event was defined as a period of time during which arterial oxygen saturation was less than 90%. 29 patients were enrolled in the intervention group and 156 patients were previously enrolled in the control group as part of an earlier study. The median number of apneic events in the control group was 7 compared to 0 in the intervention group. The intervention group experienced apnea less than 1% of the total procedure time compared to 17% in the control group (p < 0.001). There were no desaturation events observed in the 29 patients in the intervention group. In contrast, 27 out of 156 patients in the control group experienced a desaturation event. Average AUC of patients in the control group was 70%-s (time (s) * oxygen saturation below < 90%) (95% CI 32.34-108.60%) whereas the average AUC in intervention group patients was 0%-s (% time (s) * oxygen saturation < 90%) (95% CI 0-0%), p = 0.01. This preliminary study found that CPAP via a tight-fitting mask may be an effective tool to reduce the incidence and duration of obstructive apneic events as well as hemoglobin oxygen desaturation during lower endoscopy procedures that use propofol and fentanyl for sedation.Clinical Trial Registration ClinicalTrials.gov ID: NCT02623270. https://clinicaltrials.gov/ct2/show/NCT02623270 .

A contemporary review of obstructive sleep apnea.

This review provides a contemporary review of sleep apnea with emphasis on definitions, epidemiology, and consequences. Amyloid β-42 is one of the main peptides forming amyloid plaques in the brains of Alzheimer patients. Poorer sleep quality and shorter sleep duration have been associated with a higher amyloid burden. Decreased sleep time in the elderly is a precipitating factor in amyloid retention. Studies have shown that the dysregulation of the homeostatic balance of the major inhibitory and excitatory amino acid neurotransmitter systems of gamma-aminobutyric acid (GABA) and glutamate play a role in sleep disordered breathing (SDB). Untreated sleep disordered breathing (obstructive sleep apnea and/or central sleep apnea) are an important cause of medical mortality and morbidity. OSA is characterized by recurrent episodes of partial or complete collapse of the upper airway during sleep followed by hypoxia and sympathetic activation. Apneic events are terminated by arousal, followed by increases in pulse and blood pressure, and re-oxygenation and the release of inflammatory factors. Individuals with OSA have an increased risk of developing atrial fibrillation. Hypoxemia and poor sleep quality because of OSA increase the risk of cognitive decline in the elderly.

Increased Oxidative Stress, Loop Gain And The Arousal Threshold Are Clinical Predictors Of Increased Apnea Severity Following Exposure To Intermittent Hypoxia.

PurposeWe determined if oxidative stress prior to sleep onset is correlated to loop gain (LG) and the arousal threshold (AT) during non‐rapid eye movement (NREM) sleep. We also explored if LG and AT are correlated with apnea severity and indices of upper airway collapsibility during NREM sleep.MethodsThirteen male participants with obstructive sleep apnea (apnea–hypopnea index > 5 events/hr) were administered an antioxidant or placebo cocktail while exposed to mild intermittent hypoxia in the awake state. Thereafter, loop gain and measures of arousal, apnea severity and upper airway collapsibility were ascertained during NREM sleep.ResultsModification in oxidative stress (i.e., 8-hydroxy-2-deoxyguanosine) prior to sleep onset was correlated to LG (r = 0.8, P = 0.003), the number (r = 0.71, P = 0.01) and duration (r = 0.63, P = 0.04) of apneic events and the percentage of time breathing was stable (r = −0.66, P = 0.03) during sleep. Using a forward stepwise regression analysis, our results showed that LG, AT, the ventilatory response to arousal and nadir end-tidal carbon dioxide were determinants of the apnea–hypopnea index (P value range = 0.04–0.001). In addition, the AT was a predictor of measures of upper airway collapsibility, including the hypopnea/apnea + hypopnea ratio and the degree of flow reduction that accompanied hypopneic events (P < 0.001).ConclusionModifications in oxidative stress following exposure to intermittent hypoxia during wakefulness are positively associated with loop gain and apnea severity during NREM sleep. Moreover, an increase in the arousal threshold is a predictor of increased upper airway collapsibility.

EFFICACY OF A NOVEL DEVICE TO DETECT, ALERT AND RESOLVE NEONATAL APNEA - PILOT STUDY

Objective: To measure the accuracy of a novel device in detecting Bradycardia andDesaturation (B&amp;D) events and to determine its efficacy in resolving apneas innewborns with comparison to standard monitor (which only detects B&amp;D eventsand alerts).Design: This was a prospective observational study.Setting: Sick Newborn Care Unit of a large tertiary referral hospital in Hyderabad,India.Methods: 31 newborns were provided with a novel device, which monitored oxygensaturation and pulse rate and alarmed when values dropped below a set thresholdwhich is referred as an event, henceforth. The novel device also provided footstimulation in response to above-mentioned events. When the monitor alarmed, anurse attended to the baby to confirm whether the baby was breathing and whetherthe event had been resolved by the device. If the event had not resolved, appropriateaction as per the standard-of-care was performed.Results: The novel device “ApneBootTM” positively detected B&amp;D events 94.03% oftimes as compared to the standard reference monitor. 56 of 67 observed B&amp;D eventswere visually confirmed to be apneas, indicating that 83.6% of B&amp;D eventscoincided with apneas. Of the 56 apneic events, 50 were central apneas, of which 35were resolved by the novel device, making the device’s efficacy of apnea resolution70%.Conclusion: The results of the study indicate that this novel device “ApneBootTM”is very effective in detecting and alarming B&amp;D events, which coincides with theapnea, and resolving it by providing foot stimulation.Keywords: Novel Device, Neonatal Apnea, Low Birth Weight, Body Temperature,Kangaroo Mother Care, Community Health,

Effect of Eye Masks on Neonatal Stress Following Dilated Retinal Examination

Although screening examinations for retinopathy of prematurity (ROP) prevent blindness, they are physiologically stressful for infants. Photosensitivity during mydriasis may contribute to postexamination stress, and reducing light stimulation may make infants more comfortable. To determine the effect of a phototherapy mask worn during mydriasis on infant stress in the 12-hour period following ROP screening. The Effect of Eyemasks on Neonatal Stress Following Dilated Retinal Examination (MASK-ROP) randomized clinical trial with patient recruitment from April 2016 to June 2017 at neonatal intensive care units at St Michael's Hospital and Sunnybrook Health Sciences Center in Toronto, Ontario, Canada. A consecutive series of infants with birth weight of less than 1500 g and/or gestational age of less than 32 weeks undergoing their first ROP screening were analyzed beginning in July 2017. Analysis was intention to treat. Patients were randomized to wear a phototherapy mask for a minimum of 4 hours after dilating drop instillation in addition to standard comfort measures. Number of desaturation, bradycardic, or apneic events during the 12-hour postexamination period. Of 51 infants who were examined, 28 (54.9%) were randomized to the treatment group (ie, used a mask) and 23 (45.1%) to the control group. Overall, 10 (35.7%) and 13 infants (56.5%) received ventilator support at the time of examination in the treatment and control groups, respectively. The mean (SD) gestational age was 27.9 (2.4) weeks, 32 (63%) were boys, and the mean (SD) birth weight was 1058.6 (312.0) g. The number of all stressful events were lower in the treatment group compared with controls in the 12-hour postexamination period, adjusted for events prior to examination and ventilation status (mean [95% CI] events, 1.0 [0.6-1.8] vs 1.7 [1.0-1.7]; rate ratio [RR], 0.57; 95% CI, 0.3-1.2; P = .12). Risk factors associated with increased stress included younger gestational age (RR, 1.32; 95% CI, 1.2-1.5 per week), lower birth weight (RR, 1.39; 95% CI, 1.2-1.5 per 100 g), ventilator support around the time of examination (RR, 2.67; 95% CI, 1.3-5.6), intraventricular hemorrhage (RR, 3.78; 95% CI, 1.9-7.3), and hyponatremia (RR, 3.42; 95% CI, 1.8-6.6). No adverse events occurred while using eye masks. This randomized clinical trial found that light sensitivity may play a role in stress observed in the late postexamination period. However, unequal distribution of infants receiving ventilator support placed certain neonates at higher risk of stress, and the clinical significance of this intervention's benefit could not be concluded with confidence. ClinicalTrials.gov identifier: NCT03824782.

S6B-09 SESSION 6B: HFM ROBIN - PART I PSG-BASED PHENOTYPICAL CHARACTERIZATION OF OSA IN ROBIN SEQUENCE INCLUDING AROUSAL AND SLEEP-STAGE SPECIFIC INDICES

Introduction: Robin sequence (RS) is a top cause of obstructive sleep apnea (OSA) in early life. Most studies have focused on understanding anatomic factors leading to OSA and changes in apnea-hypopnea index (AHI) on polysomnography (PSG), but little is known about other PSG features of OSA in RS. The goal of this study was to compare OSA features in newborns with RS vs. infants with OSA using PSG-based determination of arousal responses and sleep-stage specific respiratory indexes. Methods: We included 10 newborns with RS (mean age 1 month) and 20 non-syndromic infants aged 0–2 years (10 non-RS with severe OSA and 10 controls without OSA). We obtained standard OSA severity parameters (OAHI, AHI and RDI) and used raw data to calculate sleep-stage specific indexes (REM vs. NREM) as well as position-specific indexes (supine vs. non-supine). For arousal responses we used respiratory arousal indexes correlated with individual’s AHI. Impact of OSA in gas exchange was assessed by SpO2 values, CO2 values and correlation with AHI. Results: All standard OSA parameters (AHI, OAHI and RDI), gas-exchange values, sleep-stage specific indexes and position-specific indexes showed similar distribution in newborns with RS and in non-RS infants with OSA. AHI correlated strongly with intermittent hypoxemia (O2 desaturation index) in the non-RS group with OSA (R-sq=93%, P <0.01) but only moderately in RS newborns (R-sq=62%, P=0.01). In both OSA groups AHI correlated with sustained hypoxemia (time <90%) (non-RS R-sq=86%, P<0.01; RS R-sq=73%, P<0.01) as well as with nadir SpO2 (non-RS R-sq=84%, P<0.01, RS R-sq=81%, P<0.01). Non-RS infants with OSA exhibited significant correlation between AHI and respiratory arousal indexes (R-sq 72%, p<0.01), however, RS newborns showed no correlation (R-sq 28%, p=0.11), particularly during REM sleep (R-sq 6%, p=0.49). Conclusion: Newborns with RS and OSA seem to have reduced arousal mechanisms to terminate apneic events, particularly during REM sleep. This may be due to young age and the trend of RS babies to have less intermittent hypoxemia, an important arousal trigger in OSA. We believe PSG-based characterization of arousal and sleep-stage specific indexes in RS may contribute to determine the best candidates for surgical correction by identifying individuals with higher risk for severe OSA due to a combination of anatomical factors and reduced arousal mechanisms to terminate apneic events.

Sleep disturbances in patients with amyotrophic lateral sclerosis: current perspectives.

Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron disease inevitably leading to generalized muscle weakness and premature death. Sleep disturbances are extremely common in patients with ALS and substantially add to the burden of disease for both patients and caregivers. Disruption of sleep can be caused by physical symptoms, such as muscle cramps, pain, reduced mobility, spasticity, mucus retention, and restless legs syndrome. In addition, depression and anxiety may lead to significant insomnia. In a small subset of patients, rapid eye movement (REM) sleep behavioral disorder may be present, reflecting neurodegeneration of central nervous system pathways which are involved in REM sleep regulation. With regard to overall prognosis, sleep-disordered breathing (SDB) and nocturnal hypoventilation (NH) are of utmost importance, particularly because NH precedes respiratory failure. Timely mechanical ventilation is one of the most significant therapeutic measures to prolong life span in ALS, and transcutaneous capnometry is superior to pulse oxymetry to detect NH early. In addition, it has been shown that in patients on home ventilatory support, survival time depends on whether normocapnia, normoxia, and elimination of apneic events during sleep can be reliably achieved. Several studies have investigated sleep patterns and clinical determinants of sleep disruption in ALS, but exact prevalence numbers are unknown. Thus, constant awareness for sleep-related symptoms is appropriate. Since no curative treatment can be offered to affected patients, sleep complaints should be thoroughly investigated in order to identify any treatable etiology and improve or stabilize quality of life as much as possible. The use of hypnotics should be confined to palliation during the terminal phase and refractory insomnia in earlier stages of the disease, taking into account that most compounds potentially aggravate SDB.

Apnea events in neonatal age: A case report and literature review

BackgroundAmong the most common autonomic signs visible in preterm neonates, apnea can represent the first sign of several neurologic and non-neurologic disorders, and seizure is a relatively infrequent cause. Herein authors present a case of neonatal autonomic apnea, discussing the polygraphic video-EEG features of this pathological entity and the differential diagnosis with central apnea and autonomic apnea. Case reportA female preterm Caucasian infant (29 + 4 weeks' gestational age (GA)), first twin of a twin pregnancy, at birth was intubated and surfactant administration was performed. She was ventilated via invasive ventilation for three days, with subsequent weaning with non-invasive ventilation for other two days, when she stopped requiring any ventilator support. After one week the ventilation weaning, the child presented episodes of cyanosis associated with sudden oxygen desaturation, skin pallor, apnea, and bradycardia. Therefore, the child underwent a continuous video-eeg recording with polygraphic study. The exam showed the presence of apneic episodes with an abrupt and clear start, associated with oxygen desaturation at 70%, with minimal thoracic effort at onset, and then evolving into central apnea. Central apnea lasted about 16 s and presented clear start- and end-points. These episodes were also associated with suppression of the EEG trace in frequency and amplitude, and after about 10 s of central apnea an abrupt decrease of the child's heart rate (more than 50% variation, from 160 bpm to 65 bpm) was recorded. In the suspect of epileptic apneas of autonomic origin, a therapy with oral Levetiracetam, at a starting dose of 10 mg/Kg/day, then increased up to 40 mg/Kg/day, was initiated, and after about 48 h the first administration of the anticonvulsant therapy, no new episodes of cyanosis or electrical apneas were recorded. HypothesisHerein the authors suggest to consider the diagnosis of autonomic seizures in those neonates with apneic events associated with EEG suppression.Considering that apnea events are not only present in preterm infants but also in term neonates, it is mandatory to diagnose in this context neonatal seizures for a correct diagnosis and a proper therapeutic choice.

Non-contact Apnea-Hypopnea Index Estimation using Near Infrared Video.

Sleep apnea is a highly prevalent and underdiagnosed sleep disorder characterized by repeated intermittent interruptions to breathing. Sleep apnea severity is measured with the apnea-hypopnea index (AHI), defined as the number of apnea or hypopnea events per hour of sleep. We hypothesize that respiratory related motion features extracted from infrared video can be used to reliably estimate AHI. The 3 feature variables chosen for apneic event estimation, and separately for sleep versus awake estimation, were: the estimated respiratory rate, the magnitude of respiratory movement, and the amount of movements. Leave-one-person-out cross validation on data from 19 participants was used to train and test a random forest binary classifier to detect apneas and hypopneas. Linear regression of the number of estimated events over estimated sleep duration and the total duration of estimated apneic events over estimated sleep duration was used to estimate AHI. Sleeping versus awake segments was estimated with mean ± standard deviation accuracy of 76.0% ± 17.7%. AHI was estimated with correlation coefficient of 0.76 (p <; 0.01) to the clinical gold standard AHI. Accuracy of 78.9% was achieved for classifying AHI ≥ 15, with sensitivity of 70.0%, specificity of 88.9%, and precision of 87.5%. Motion features extracted from infrared video are concluded to be suitable for estimation of AHI.